Duffel bag



FIG. 1 is a right side view in elevation showing my design without its strap;

FIG. 2 is a left side view in elevation thereof;

FIG. 3 is a top view in plan thereof;

FIG. 4 is a bottom view in plan thereof;

FIG. 5 is a front view in elevation thereof;

FIG. 6 is a rear view in elevation thereof;

FIG. 7 is a right side view in elevation showing my design with its strap;

FIG. 8 is a left side view in elevation thereof;

FIG. 9 is a top view in plan thereof;

FIG. 10 is a front view in elevation thereof; and,

FIG. 11 is a rear view in elevation thereof.

Broken lines appearing throughout the drawings as circular elements represent vents and are not part of the claimed design. 

The ornamental design for a duffel bag, as shown and described. 